I really love the Logitech MX Performance mouse wireless. It's a real pleasure to use in both OS X and Windows both for general use and especially for gaming where I simply must have a real two button mouse.
This mouse isn't cheap as mice go but it is worth it. It is very comfortable with a shape that contours well to the hand. It is rechargeable so you do not need to be constantly buying batteries for it. What is really nice too is that it includes a USB cable with a mini connector that plugs into the front of it, to recharge it while allowing you to continue using it. There is also a standard wall outlet charging cable included as well.
It offers a great blend of comfort, convenience and compatibility and I find it works very well for gaming.
Oh, and it does include OS X support and installs a very nice Control Center app into your System Preferences to configure the buttons, etc. as desired.